Re: [Chicken-janitors] #885: pty egg: example doesn't work

[Chicken Trac]

#885: pty egg: example doesn't work
-------------------------+--------------------------------------------------
  Reporter:  megane      |       Owner:  ashinn  
      Type:  defect      |      Status:  assigned
  Priority:  minor       |   Milestone:          
 Component:  extensions  |     Version:  4.7.x   
Resolution:              |    Keywords:  pty     
-------------------------+--------------------------------------------------
Changes (by sjamaan):

  * owner:  => ashinn
  * status:  new => assigned
  * milestone:  4.8.0 =>


Comment:

 There seem to be several problems with this egg and the example.

 One is that {{{errno}}} seems to be bound to a '''procedure''' (the
 "errno" procedure from the library unit) rather than the foreign value
 (this could be a bug in the module system?? possibly fixed already??) so
 it will never be {{{eq?}}} to {{{_ewouldblock}}}. Also, while
 {{{EWOULDBLOCK}}} is identical to {{{EAGAIN}}} on my system, I'm not sure
 it's everywhere; might want to add that to the check.

 You could re-use {{{errno/wouldblock}}} and {{{errno/again}}} from the
 POSIX unit, by the way.

 Furthermore, the library doesn't compile on (Net)BSD because there it
 needs to include {{{util.h}}} (and also link to libutil, which for some
 odd reason OS X doesn't require?).

 The example, if used literally, will call ssh with a nonexistant hostname,
 so it probably won't really work and it uses some undefined {{{(gui-get-
 password)}}} procedure.  For now I just added a comment saying that it's
 not defined and the user needs to define it.  Not sure if this is
 something you meant to take out or something?

 If I insert a {{{(sleep 10)}}} as first call in the lambda before the
 {{{peek-char}}} call, I get an error about this gui procedure, so I guess
 somehow the child process hasn't started yet or the PTY hasn't been fully
 set up at the time of the peek-char call.  That error message is actually
 the string that belongs to {{{EAGAIN}}}/{{{EWOULDBLOCK}}}, so I don't
 quite see why the loop isn't working.

 I'll remove the milestone, since this has nothing to do with the Chicken
 release itself.

-- 
Ticket URL: <http://bugs.call-cc.org/ticket/885#comment:1>
Chicken Scheme <http://www.call-with-current-continuation.org/>
Chicken Scheme is a compiler for the Scheme programming language.